File:Clinker horizon (Wasatch Formation, Lower Eocene; coal fire metamorphism at 19 ka, Late Pleistocene; hills east of Buffalo, Powder River Basin, Wyoming, USA) (19943573529).jpg
![File:Clinker horizon (Wasatch Formation, Lower Eocene; coal fire metamorphism at 19 ka, Late Pleistocene; hills east of Buffalo, Powder River Basin, Wyoming, USA) (19943573529).jpg](https://upload.wikimedia.org/wikipedia/commons/thumb/d/d4/Clinker_horizon_%28Wasatch_Formation%2C_Lower_Eocene%3B_coal_fire_metamorphism_at_19_ka%2C_Late_Pleistocene%3B_hills_east_of_Buffalo%2C_Powder_River_Basin%2C_Wyoming%2C_USA%29_%2819943573529%29.jpg/800px-thumbnail.jpg?20191206020041)
Original file (4,000 × 2,347 pixels, file size: 3.63 MB, MIME type: image/jpeg)
Captions
Captions
Summary
[edit]DescriptionClinker horizon (Wasatch Formation, Lower Eocene; coal fire metamorphism at 19 ka, Late Pleistocene; hills east of Buffalo, Powder River Basin, Wyoming, USA) (19943573529).jpg |
Clinker horizon in Wyoming, USA. Clinker is a scarce, odd rock. It occurs adjacent to former coal bed horizons. Coal is combustible (that’s why coal is used as an energy source in human society). Coal beds can ignite accidentally or naturally. Accidental coal bed ignition often leads to environmental disaster areas (for example, Centralia, Pennsylvania, USA). Natural coal bed fires can be initiated by lightning strikes, grass fires, forest fires, or spontaneous combustion. Some ancient coal beds in the geologic record have burned away, leaving behind clinker beds. “Clinker” is the term for thermal metamorphic rocks (combustion metamorphic rocks) that have been significantly altered by the heat of burning coal beds. The appearance and color of clinker varies significantly. Scoriaceous to semivitreous clinker is called buchite, which formed by partial fusion/melting. Some sedimentary rocks adjacent to coal fires have melted to form paralava. Subsequent cooling and shrinking can form pseudocolumnar jointing in clinker horizons. Non-vesicular clinker that resembles unglazed porcelain is called porcellanite (a.k.a. porcelanite). Clinker having numerous, differently-oriented, angular clasts jumbled together is called clinker-bed breccia, which forms by shifting and collapse of beds overlying a burned-out coal horizon. Some early explorers of the American Great Plains, not knowing the non-volcanic origin of this material, called natural clinker “pumice” or “scoria”. Clinker is still called "scoria" today in Wyoming, Montana, and North Dakota, where conspicuous, orangish-brown to reddish-brown clinker horizons commonly cap hilltops and buttes. The terms "buchite" and "porcellanite" are not restricted to clinker lithologies. To prevent confusion, these terms should always be combined with the term "clinker" to refer to rock types associated with coal fires (i.e., "buchite clinker" and "porcellanite clinker"). Stratigraphy & age: siliciclastic sedimentary rock overlying the Healey-Ucross/Lake de Smet Coal Zone in the Wasatch Formation (Lower Eocene), thermally metamorphosed by a coal fire at 19 ka (near-latest Pleistocene) Locality: hills north of Interstate 90 west-bound hilltop rest area, east of the town of Buffalo, northern Johnson County, western Powder River Basin, northern Wyoming, USA Example references on clinker of the Powder River Basin: Foit, F.F., R.L. Hooper & P.E. Rosenberg. 1987. An unusual pyroxene, melilite, and iron oxide mineral assemblage in a coal-fire buchite from Buffalo, Wyoming. American Mineralogist 72: 137-147. Heffern, E.L., P.W. Reiners, C.W. Naeser & D.A. Coates. 2007. Geochronology of clinker and implications for evolution of the Powder River Basin landscape, Wyoming and Montana. Geological Society of America Reviews in Engineering Geology 18: 155-175. Heffern, E.L., P.W. Reiners & C.A. Riihimaki. 2013. Clinker distribution and age in the Powder River Structural Basin. Montana Bureau of Mines and Geology Geologic Map 64. |
Date | |
Source | Clinker horizon (Wasatch Formation, Lower Eocene; coal fire metamorphism at 19 ka, Late Pleistocene; hills east of Buffalo, Powder River Basin, Wyoming, USA) |
Author | James St. John |
Licensing
[edit]![w:en:Creative Commons](https://upload.wikimedia.org/wikipedia/commons/thumb/7/79/CC_some_rights_reserved.svg/90px-CC_some_rights_reserved.svg.png)
![attribution](https://upload.wikimedia.org/wikipedia/commons/thumb/1/11/Cc-by_new_white.svg/24px-Cc-by_new_white.svg.png)
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
![]() |
This image was originally posted to Flickr by James St. John at https://flickr.com/photos/47445767@N05/19943573529 (archive). It was reviewed on 6 December 2019 by FlickreviewR 2 and was confirmed to be licensed under the terms of the cc-by-2.0. |
6 December 2019
File history
Click on a date/time to view the file as it appeared at that time.
Date/Time | Thumbnail | Dimensions | User | Comment | |
---|---|---|---|---|---|
current | 02:00, 6 December 2019 | ![]() | 4,000 × 2,347 (3.63 MB) | Ser Amantio di Nicolao (talk | contribs) | Transferred from Flickr via #flickr2commons |
You cannot overwrite this file.
File usage on Commons
There are no pages that use this file.
Metadata
This file contains additional information such as Exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it. If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of the original file. The timestamp is only as accurate as the clock in the camera, and it may be completely wrong.
Camera manufacturer | Canon |
---|---|
Camera model | Canon PowerShot D10 |
Exposure time | 1/1,000 sec (0.001) |
F-number | f/4.5 |
ISO speed rating | 80 |
Date and time of data generation | 14:30, 4 July 2015 |
Lens focal length | 14.303 mm |
Image title | |
Width | 4,000 px |
Height | 3,000 px |
Bits per component |
|
Pixel composition | RGB |
Orientation | Normal |
Number of components | 3 |
Horizontal resolution | 180 dpi |
Vertical resolution | 180 dpi |
Software used | Adobe Photoshop Elements 13.0 (Macintosh) |
File change date and time | 22:43, 29 July 2015 |
Y and C positioning | Co-sited |
Exif version | 2.21 |
Date and time of digitizing | 14:30, 4 July 2015 |
Meaning of each component |
|
Image compression mode | 3 |
APEX shutter speed | 9.96875 |
APEX aperture | 4.34375 |
APEX exposure bias | −0.33333333333333 |
Maximum land aperture | 4.34375 APEX (f/4.51) |
Metering mode | Pattern |
Flash | Flash did not fire, compulsory flash suppression |
Supported Flashpix version | 1 |
Color space | sRGB |
Focal plane X resolution | 16,460.905349794 |
Focal plane Y resolution | 16,483.516483516 |
Focal plane resolution unit | inches |
Sensing method | One-chip color area sensor |
File source | Digital still camera |
Custom image processing | Normal process |
Exposure mode | Manual exposure |
White balance | Auto white balance |
Digital zoom ratio | 1 |
Scene capture type | Landscape |
Lens used | 6.2-18.6 mm |
Date metadata was last modified | 18:43, 29 July 2015 |
Unique ID of original document | DBFDA23BEC8C00FD14BC00E9E835DEC0 |